But a lot easier to buy and depending on the application a lot more compact.
Certainly to buy is the easyest way but to make myself is nice thing. I like it. I tryed to do it. But I saw my assembler knowledge is not enough for this project. I begun with the 16F857 mikro controler. I got the assembler kods from mikro controlers page. I tought that I will change this codes to hexadecimal numbers and put the mirocontrolers memory. It was not so. the MASM program gave many errors. I tryed to correct them but seems impossible for me. As I said above my knowledge was not enough. I was looking a ready project . I saw the "instructables " site and I wrote here. Perhaps some body is working on this subject and can help me. This is my story.